Background: Structural valve deterioration (SVD) is the Achilles' heel of bioprostheses. Its correlation with younger age is well known. In recent years we exclusively reserved use of small-size Mitroflow valve prostheses (LivaNova, London, United Kingdom) to an older patient population with small aortic annuli. This study aimed to assess the incidence of SVD and its effect on patient survival and need for reoperation.
Materials and methods: Two hundred five patients (aged 75.9 ± 5.3 years; range, 62-92 years) underwent aortic valve replacement with a 19-mm or 21-mm Mitroflow valve prosthesis between 2005 and 2011. The great majority was female (n = 170; 83%). In half of patients it was an isolated procedure. All valve prostheses were implanted in a supra-annular position using pledgeted sutures. A 19-mm valve was implanted in 93 patients (45.3%), whereas in 112 patients (54.6%) a 21-mm valve was used.
Results: Twenty-three patients (11.2%) were diagnosed with early SVD by echocardiography. Average time from surgery to diagnosis of SVD was 64.3 ± 26.8 months. Ten patients needed a reoperation for SVD. Average time from surgery to a second operation was 45.7 ± 35.7 months. Overall survival was 64.5% and 42.3% at 5 and 9 years, respectively. Cumulative freedom from SVD at 5 and 9 years was 94.8% ± 1.6% and 77.4% ± 5.4%, respectively. In 4 patients death was linked to the presence of SVD. There were no differences in mortality, reoperation, or SVD between the 2 Mitroflow valve sizes.
Conclusions: Small-size Mitroflow pericardial valve prostheses have shown a worrisome incidence of SVD even in patients aged >70 years. Based on this experience we have discontinued their use.
Keywords: aortic valve; heart valve prosthesis; structural valve deterioration.
Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.